Subject: Re: bug#3400: bug in add-text-properties

From: Werner LEMBERG <[email-masked]>
Date: Fri, 29 May 2009 09:00:50 +0200 (CEST)

> Point is at position 1 (i.e. just before the char "1" rather than
> before the char "A"), so it makes sense for C-h = to return data
> about that position rather than about some other position one line
> down.

I disagree.  Whereever point is, it should report the character after
point which is accessible (this is, visible).  Perhaps it makes sense
to add a red warning message in the output of `C-x =' that point is
not located right before the displayed character.

If we had a small line instead of a blinking, block-like cursor (as it
is used with, say, OpenOffice), I could accept your argumentation.
But the visual effect is overwhelming, and it is extremely confusing
if the optical appearance differs so much from the `theoretical'
result.

>> Actually, there is no way to retrieve information from `A' at all.
> 
> Your `intangible' span basically requests "12345\nA" to be treated
> as one indivisible entity, so it's indeed difficult to get info
> about most of those individual chars.

Hmm.  IMHO, the same argumentation as above holds.

> if you're not 200% sure you absolutely need `intangible', then don't
> use it.  It's a nasty beast.

Indeed.  But for my particular needs -- filtering out some lines, then
searching and editing the visible ones only without accidentally
editing invisible stuff, it seems that `intangible' is still
necessary, and probably will stay so.

    Werner